Clinically Indicated, Equitable Care for Ischemic Heart Disease in CKD: A Call to Action
Authors: Vikram Fielding-Singh, Glenn M. Chertow
Journal: Journal of the American Society of Nephrology (2023)

Approximately 20 years ago, studies began to report lower rates of invasive care to treat acute coronary syndromes in persons with kidney disease compared with persons with normal or near-normal kidney function.1–3 For a population with an exceptionally high prevalence of cardiovascular risk factors, inequity in the deployment of clinically indicated invasive care for acute myocardial infarction or unstable angina is particularly distressing. While treatments for cardiovascular and kidney disease have improved over the same time frame, inequities in care delivery have remained. In this issue of the JASN, Weisbord et al. report results from a cohort of nearly 65,000 Veterans hospitalized with acute coronary syndromes between 2013 and 2017.4 Accounting for an array of demographic, clinical, and laboratory data, the investigators found that patients with moderate to advanced (stages G3a, G3b, and G4) CKD were significantly less likely to be treated with clinically indicated invasive cardiac care than those without CKD. Nonuse of clinically indicated coronary angiography and the interventions that might follow, including percutaneous coronary intervention or coronary artery bypass graft surgery, was associated with a 39% increased risk of all-cause mortality at 6 months. Weisbord et al. conducted a series of comprehensive and creative analyses using data from the Department of Veterans Affairs (VA) health care system, the largest integrated health care system in the United States. The investigators incorporated a combination of vital signs, laboratory values, and natural language processing of clinical notes from the electronic health record to calculate Global Registry of Acute Coronary Events (GRACE) risk 2.0 scores for each patient to determine the appropriateness of invasive cardiac care. They employed target trial emulation to design a comparison of use versus nonuse of clinically indicated invasive cardiac care in patients with CKD, analyzed using propensity score matching. The investigators used numerous sensitivity analyses to confirm their findings, including stratified analyses by GRACE score and by CKD stage, and a sensitivity analysis of an outcome that should not have been affected by performance of invasive cardiac care (i.e., pneumonia). The analyses were sophisticated and exceptionally comprehensive, and the findings were unusually consistent across all analyses conducted. There are some limitations worth noting. Because the data were derived from the VA, the cohort was disproportionately male, limiting the generalizability of the findings to women with CKD.5 Similarly, patients with CKD stage 5 were excluded because the relative risks and benefits of invasive cardiac care in these patients are unclear. It is noteworthy that the most recent revascularization guidelines from the American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography and Interventions do not distinguish recommendations by stages of CKD.6 Like other examples of high-quality health services research, the report by Weisbord et al. should motivate additional research—in this case to understand the source of, and ongoing reasons for, inequities of care. For example, one might compare the degree to which clinically indicated invasive cardiac care is delivered to patients with normal or near-normal kidney function as well as with patients with chronic noncardiovascular conditions (e.g., those with chronic obstructive pulmonary disease or chronic liver disease) to determine whether the reluctance to proceed with clinically indicated invasive cardiac care relates to a general fear of complications, therapeutic nihilism, or a more kidney-specific fear of inducing injury related to exposure to radiocontrast, as we suspect. Finally, although issues related to short-term mortality are of high priority, the investigators might consider estimating the effects of clinically indicated invasive cardiac care on CKD progression. It is plausible that the provision of such care could attenuate progression of CKD by enhancing cardiovascular function and reducing the risk of heart failure. Doing so might counterbalance any hazards—short or long term—of radiocontrast-associated nephropathy. We have been made aware of disparities in health care delivery for several decades, and yet, they persist. In the midst of major advances in biomedicine and precision health, gross inequities in health and health care represent tragic failures of our health care system. While we aim in future years to promote health equity and abolish disparities in the delivery of health care related to age, sex, race, ethnicity, sexual orientation, gender identity, and other demographic features, so too should we aim to provide equitable cardiovascular (and noncardiovascular) care to the roughly 10% of adults with CKD. The work of Weisbord et al. should catalyze us to better understand the underlying reasons for these inequities and guide us to correct them.